Sanitising and disinfecting soap or cleaning compositions are of great benefit to individuals, since proper use generally may reduce the number of germs and pathogens the individual is exposed to. Thus, such compositions may for instance play an important role in reducing the occurrence and spread of infectious diseases.
Sanitising and disinfecting soap compositions comprising chlorine-based antimicrobial agent such as triclosan are known. Such compositions require a rather long contact time to provide efficacious antimicrobial action. In practice, users, in particular children, do not spend a long time on cleansing and as a result cleaning with such compositions does not provide adequate prevention from surface or topical infection or adequate protection against diseases. The user, in spite of cleaning his hands, is generally likely to end up with relatively inadequate bacterial removal from his skin. Therefore, he may cause contamination of further animate and/or inanimate surfaces and contribute to the spreading of pathogens and consequent diseases. Users in general and children in particular who wash contaminated hands before meals with slow-acting antimicrobial compositions for relatively short time are at risk of contracting diseases.
Similarly in the area of hard surface cleaning, e.g. cleaning of floors, table tops or utensils, the antimicrobial in the compositions are in contact with the substrate for less than a few minutes after which the surface is either wiped off or rinsed with water. These short time scales of cleaning action are ineffective in providing the desired benefit since most known antimicrobials commonly used in such products take many minutes to hours to provide the desired kill of microbes.
Therefore, there is a need of providing a composition that—upon application—provides relatively more efficacious antimicrobial action during a relatively short cleaning period, preferably about 30 seconds or less.
A well-established class of antimicrobially active compounds are phenolic compounds [P A Goddard and K A McCue in “Disinfection, Sterilisation and Preservation”, ed. S S Block, 5th edition, Lippincott, Williams and Wilkins, Philadelphia, 2001 pp. 255-282]. However, not every phenolic compound is suitable as an antimicrobial agent. Moreover, many phenols—even if they are antimicrobially active—may exhibit undesirable side-effects, such as corrosiveness, malodour and irritating or sensitising effects when applied on the human or animal skin. In addition, small changes to molecular structure may in general strongly affect both the desired and the undesired effects in a generally unpredictable way.
A particularly well-known group of phenolic compounds are halogenated phenolics. However, there are concerns about the usage of chlorinated phenols as antimicrobials and herbicides, since they are perceived as pollutants, and are often associated with environmental toxicity, bioaccumulation and low biodegradability [J P Voets et al, J. Appl. Bact. vol 40, p. 67-72 (1976); “Chlorophenols in the terrestrial environment” J Jensen, Reviews of environmental contamination and toxicology, Vol 146 pp 25-51 (1996)).
WO 2010/046238 A1 describes an effective antimicrobial composition which provides rapid kill of pathogenic bacteria and which comprises 0.01 to 5% by weight of thymol, 0.01 to 5% by weight of terpineol and a carrier. WO 2010/046238 A1 also discloses a method of disinfecting a surface including the step of applying the above composition to the surface.
EP 0 791 362 A2 discloses a composition comprising a peroxygen bleach, from 0.003% to 5% by weight of the total composition of a cyclic terpene or a derivative thereof and from 0.003% to 5% by weight of the total composition of a phenolic compound. The composition can be used to disinfect various surfaces, including animate and inanimate surfaces. It was found that the use of a cyclic terpene and/or a derivative thereof (e.g. eucalyptol) together with a phenolic compound (e.g. eugenol, carvacrol, ferulic acid) results in a synergistic effect on disinfecting performance. Suitable cyclic terpenes include any mono- or polycyclic compound including at least one isoprenic unit, preferably 1 or 2, said isoprenic unit may comprise one or more hetero atoms, preferably, oxygen, and said isoprenic unit may be substituted at any carbon by H, a linear or branched, saturated or unsaturated hydrocarbon chain, an alkoxylated hydrocarbon chain, or an aryl chain having from 1 to 20 carbon atoms, more preferably from 1 to 4. Highly preferred cyclic terpenes or derivatives thereof are limonene, menthol, eucalyptol, terpineol and mixtures thereof.
The phenolic compounds of the composition according to EP 0 791 362 A2 have the following formula:
wherein R, R1, R2, R3, R4 independently are H, a linear or branched, saturated or unsaturated hydrocarbon chain having from 1 to 20 carbon atoms, an alkoxylated hydrocarbon chain according to the formula Ra(A)n wherein Ra is a linear or branched, saturated or unsaturated hydrocarbon chain having from 1 to 20 carbon atoms, wherein A is butoxy, propoxy and/or ethoxy, and n is an integer of 1 to 4, or an aryl chain having from 1 to 20 carbon atoms. Eugenol, carvacrol and ferulic acid are preferred phenolic compounds. EP 0 791 362 A2 also discloses a process of disinfecting an inanimate surface, in particular fabrics, with the above composition. In different modes of fabric disinfecting, contacting times from 1 to 30 minutes, or from 1 minute to 24 hours are preferred.
U.S. Pat. No. 6,152,152 discloses a method for washing dishes, which comprises applying to an absorbent implement an undiluted liquid dishwashing composition comprising a) from 10% to 60% by weight of a surfactant, b) from 1% to 15% by weight of a hydrotrope selected from the group consisting of salts of cumene sulfonate, toluene sulfonate, xylene sulfonate, benzene sulfonate and mixtures thereof; and c) from 0.1% to 3% by weight of the total composition of an unsaturated aliphatic terpene alcohol or derivative, and d) a phenolic compound. The phenolic compound is of the same formula as given for EP 0 791 362 A2 above. The preferred aliphatic terpene alcohol is geraniol; preferred phenolic compounds are eugenol, thymol, and mixtures thereof. It was found that such dishwashing compositions can fulfil the purpose of reducing or eliminating bacterial growth on absorbing dish implements. To achieve this, the dish implement is preferably contacted, e.g. soaked with neat product and left to dry.
WO 04/035723 is directed to concentrated cleaning and/or disinfecting compositions which bloom when diluted in water. It discloses a hard surface cleaning concentrate composition comprising: a) from about 0.05 to about 10 wt % of a non-cationic antimicrobial agent; b) from about 1 to about 20 wt % of a water soluble organic solvent c) from about 1 to about 20 wt % of an anionic soap surfactant; d) from about 1 to about 15 wt % of a hydrocarbon diluent; e) from about 0.001 to about 20 wt % of pine oil which is at least 60% terpene alcohols; f) optionally, from about 0 to about 10 wt % of optional materials selected from dyes, colorants, pH stabilizers and buffers, non-ionic surfactants, fragrance/fragrance enhancers, viscosity modifiers, insect repellants, and light stabilizers; and g) the balance being water. Phenol based non-cationic antimicrobials are preferred. Important constituents of the pine oil include terpineol. It is shown that a composition comprising 1.50 wt % of aromatic hydrocarbons (Aromatic 200), 1.00 wt % of Pine Oil 80, 1.50 wt % of PCMX (p-chloro-m-xylenol), 2.00 wt % of isopropyl alcohol, 20 wt % of NaCOS (sodium castor oil soap—40%), 0.40 wt % of insect repellant. 73.60 wt % water and added dye provides a Log 10 reduction value of greater than 3 In a microbial reduction suspension test, after a contact time of 15 seconds, using 1:60 to 1:100 dilutions of the composition in water and one part of organism suspension (Staphylococcus aureus or Salmonella choleraesuis).
FR 2 697 133 discloses biocidal and/or biostatic compositions, comprising mono-oxygenated sesquiterpenes of general formula C15HxO, wherein x is between 20 and 26 and aromatic compounds.
Despite the general availability of antimicrobial compounds and compositions, there remains a continuous need to find alternative antimicrobial compositions and active compounds that are suitable for use in such compositions. In particular, alternative compositions providing fast antimicrobial action remain highly desirable in view of current consumer habits. Such alternatives may reduce the dependency on current raw materials. Moreover, in the field of antimicrobials, the availability of alternatives may reduce the risk of development of microbial resistance or insensitivity to particular antimicrobial compounds.
In addition, there is a continued need to reduce the total amount of active Ingredients required in such an antimicrobial composition. This need may for instance be driven by the desire for cost-efficiency, because such compositions are particularly relevant to developing countries. Moreover, reducing the amounts may also be beneficial for environmental reasons.
A particular problem of certain antimicrobial actives, and especially some phenolic compounds such as thymol is that they are generally well-perceptible due to their olfactory properties. Although the latter may—at least for some species—be appreciated in certain fragrance compositions, they are considered too intense by some users when they are applied at concentrations efficacious in rapid disinfection. Additionally, a lower concentration of odoriferous compounds or the availability of antimicrobial compounds that are less or not odoriferous allows greater flexibility to the manufacturer in providing alternative scents to his composition at lower doses. Hence there is a need to provide alternative antimicrobial compositions and methods that preferably require lower concentrations and/or have a more acceptable sensory profile.
In view of the above-observed problems and drawbacks of the prior art, it is an object of the present invention to provide alternative antimicrobial compositions, in particular antimicrobial compositions that do not depend on halogenated phenols for their antimicrobial efficacy.
It is a particular object of the invention to provide such compositions, requiring a lower dose of antimicrobial compounds.
Similarly, it is an object of the present invention to provide an antimicrobial composition in which the olfactory contribution of the antimicrobially active compounds is reduced or in which the active compound contributes to providing a consumer-acceptable or even consumer-appreciated scent.
It is another particular object of the invention to provide an antimicrobial composition that contributes to reducing the required contact time in a method for disinfection of a surface.
In particular, it is an object of the invention to provide an antimicrobial composition which gives improved disinfection during cleansing of surfaces of the human body, such as the skin and the oral cavity.
It is yet another object of the present invention to provide an alternative method for sanitising and/or disinfecting, in particular of surfaces.
It is a further object of the invention to provide a method for disinfection with a reduced disinfection time. More specifically, it is an object of the invention to provide a method, wherein the disinfection time of the method is less than 300 seconds, preferably less than 60 seconds, and more preferably less than 15 seconds.
In particular, it is an object of the invention to provide a method for disinfection that gives improved disinfection during cleansing of surfaces, in particular hard surfaces, or surfaces of the human body, such as the skin and the oral cavity.